This invention relates to an apparatus for supplying regulated direct electrical current and a method of effecting regulation of a direct current output from a switch mode regulator.
The problem to which this invention is directed relates to the problem of losses normally occasioned when attempting to provide a direct current switch mode regulated power supply with low noise.
It is well known to use a switch mode power supply to provide a regulated output.
However, using a switch mode technique inherently provides a high noise content and it has been conventional, if lower noise characteristics are required, to have the output fed into the input of a linear regulator.
A linear regulator of current design is inherently inefficient and significant power will be conventionally lost through the linear regulator with conventional circuit layouts.
Unfortunately, such inefficiency means that more power must be provided by the switch mode regulator with resultant larger heat dissipation and sizes of components becomes more of a problem.
An object of this invention is to provide an apparatus incorporating both a switch mode regulator and a linear regulator which are coupled in such a way that these can be caused to work in a more efficient way than has hitherto been the case.